<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    console.log('正直角三角形：');
    for (let i = 1; i <= 9; i++) {
        let str = '';
        for (let j = 1; j <= i; j++) {
            str += ' * '
        }
        console.log(str)
    }
</script>

<script>
    console.log('\n倒直角三角形：');
    for (let i = 1; i <= 9; i++) {
        let str = '';
        for (let j = 1; j <= 10 - i; j++) {
            str += ' * '
        }
        console.log(str)
    }
</script>

</html>